Guava (Psidium guajava Linn.) leaf extract promotes glucose uptake and glycogen accumulation by modulating the insulin signaling pathway in high-glucose-induced insulin-resistant mouse FL83B cells

2015 ◽  
Vol 50 (7) ◽  
pp. 1128-1135 ◽  
Author(s):  
Ching-Wen Liu ◽  
Yi-Cheng Wang ◽  
Chang-Chi Hsieh ◽  
Hsi-Chi Lu ◽  
Wen-Dee Chiang
Keyword(s):  
Glucose Uptake ◽  
Signaling Pathway ◽  
Insulin Signaling ◽  
High Glucose ◽  
Leaf Extract ◽  
Psidium Guajava ◽  
Insulin Signaling Pathway ◽  
Resistant Mouse ◽  
Glycogen Accumulation ◽  
Insulin Resistant

scholarly journals Sphingomyelinase has an insulin-like effect on glucose transporter translocation in adipocytes

1998 ◽  
Vol 274 (5) ◽  
pp. R1446-R1453 ◽  
Author(s):  
T. S. David ◽  
P. A. Ortiz ◽  
T. R. Smith ◽  
J. Turinsky
Keyword(s):  
Plasma Membrane ◽  
Insulin Receptor ◽  
Glucose Uptake ◽  
Signaling Pathway ◽  
Insulin Signaling ◽  
Glucose Transporter ◽  
Insulin Signaling Pathway ◽  
Glut 1 ◽  
Glut 4 ◽  
Glut 4 Translocation

Rat epididymal adipocytes were incubated with 0, 0.1, and 1 mU sphingomyelinase/ml for 30 or 60 min, and glucose uptake and GLUT-1 and GLUT-4 translocation were assessed. Adipocytes exposed to 1 mU sphingomyelinase/ml exhibited a 173% increase in glucose uptake. Sphingomyelinase had no effect on the abundance of GLUT-1 in the plasma membrane of adipocytes. In contrast, 1 mU sphingomyelinase/ml increased plasma membrane content of GLUT-4 by 120% and produced a simultaneous decrease in GLUT-4 abundance in the low-density microsomal fraction. Sphingomyelinase had no effect on tyrosine phosphorylation of either the insulin receptor β-subunit or the insulin receptor substrate-1, a signaling molecule in the insulin signaling pathway. It is concluded that the incubation of adipocytes with sphingomyelinase results in insulin-like translocation of GLUT-4 to the plasma membrane and that this translocation does not occur via the activation of the initial components of the insulin signaling pathway.

scholarly journals Exercise-Induced Muscle Damage Impairs Insulin Signaling Pathway Associated With IRS-1 Oxidative Modification

2012 ◽  
pp. 81-88 ◽  
Author(s):  
W. AOI ◽  
Y. NAITO ◽  
H. TOKUDA ◽  
Y. TANIMURA ◽  
T. OYA-ITO ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Glucose Uptake ◽  
Signaling Pathway ◽  
Muscle Damage ◽  
Insulin Signaling ◽  
Acute Exercise ◽  
Insulin Signaling Pathway ◽  
Oxidative Modification ◽  
Whole Body ◽  
Strenuous Exercise

Strenuous exercise induces delayed-onset muscle damage including oxidative damage of cellular components. Oxidative stress to muscle cells impairs glucose uptake via disturbance of insulin signaling pathway. We investigated glucose uptake and insulin signaling in relation to oxidative protein modification in muscle after acute strenuous exercise. ICR mice were divided into sedentary and exercise groups. Mice in the exercise group performed downhill running exercise at 30 m/min for 30 min. At 24 hr after exercise, metabolic performance and insulin-signaling proteins in muscle tissues were examined. In whole body indirect calorimetry, carbohydrate utilization was decreased in the exercised mice along with reduction of the respiratory exchange ratio compared to the rested control mice. Insulin-stimulated uptake of 2-deoxy-[3H]glucose in damaged muscle was decreased after acute exercise. Tyrosine phosphorylation of insulin receptor substrate (IRS)-1 and phosphatidyl-3-kinase/Akt signaling were impaired by exercise, leading to inhibition of the membrane translocation of glucose transporter 4. We also found that acute exercise caused 4-hydroxy-nonenal modification of IRS-1 along with elevation of oxidative stress in muscle tissue. Impairment of insulin-induced glucose uptake into damaged muscle after strenuous exercise would be related to disturbance of insulin signal transduction by oxidative modification of IRS-1.

A flavone derivative from Andrographis echioides leaf extract positively alters the molecular targets of insulin signaling pathway

2022 ◽  
Vol 146 ◽  
pp. 760-770
Author(s):  
Sindhu Sivalingam ◽  
Sivakumar Kandhasamy ◽  
Sivaraj Chandrasekaran ◽  
Karthikeyan Vijayan ◽  
Justin P Jacob ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Insulin Signaling ◽  
Leaf Extract ◽  
Molecular Targets ◽  
Insulin Signaling Pathway ◽  
Flavone Derivative

scholarly journals Glucose regulates the histone acetylation of gene promoters in decidualizing stromal cells

Reproduction ◽  
2019 ◽  
Vol 157 (5) ◽  
pp. 457-464 ◽  
Author(s):  
Kosuke Jozaki ◽  
Isao Tamura ◽  
Haruka Takagi ◽  
Yuichiro Shirafuta ◽  
Yumiko Mihara ◽  
...  
Keyword(s):  
Glucose Uptake ◽  
Signaling Pathway ◽  
Insulin Signaling ◽  
Stromal Cells ◽  
Insulin Signaling Pathway ◽  
Gene Promoters ◽  
Promoter Regions ◽  
Endometrial Stromal Cells ◽  
Expression Levels ◽  
Low Glucose

Decidualization stimuli activate the insulin signaling pathway and increase the glucose uptake in human endometrial stromal cells (ESCs). The inductions of prolactin (PRL) and IGF-binding protein-1 (IGFBP1), specific markers of decidualization, were inhibited by incubating ESCs under low glucose concentrations. These results suggested that decidualization stimuli activate the insulin signaling pathway, which contributes to decidualization through the increase of glucose uptake. Here, we investigated the mechanisms by which glucose regulates decidualization. ESCs were incubated with cAMP to induce decidualization. We examined whether low glucose affects the expression levels of transcription factors that induce decidualization. Forkhead box O1 (FOXO1) expression was significantly suppressed under low glucose conditions. Knockdown of FOXO1 by siRNA inhibited the expression levels of PRL and IGFBP1 during decidualization. Taken together, our results showed that low glucose inhibits decidualization by decreasing FOXO1 expression. We also examined the levels of histone H3K27 acetylation (H3K27ac), which is related to active transcription, of the promoter regions of FOXO1, PRL and IGFBP1 by ChIP assay. The H3K27ac levels of these promoter regions were increased by decidualization under normal glucose conditions, but not under low glucose conditions. Thus, our results show that glucose is indispensable for decidualization by activating the histone modification status of the promoters of PRL, IGFBP1 and FOXO1.

scholarly journals MicroRNA-506 modulates insulin resistance in human adipocytes by targeting S6K1 and altering the IRS1/PI3K/AKT insulin signaling pathway

2021 ◽  
Author(s):  
Feng-Yu Zhong ◽  
Jing Li ◽  
Yu-Mei Wang ◽  
Yao Chen ◽  
Jia Song ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Glucose Uptake ◽  
Signaling Pathway ◽  
Insulin Signaling ◽  
Underlying Mechanism ◽  
Insulin Signaling Pathway ◽  
Akt Pathway ◽  
Public Health Issue ◽  
Pathway Activation ◽  
Candidate Target

AbstractThe incidence of obesity has increased rapidly, becoming a worldwide public health issue that involves insulin resistance. A growing number of recent studies have demonstrated that microRNAs play a significant role in controlling the insulin signaling network. For example, miR-506-3p expression has been demonstrated to correlate with insulin sensitivity; however, the underlying mechanism remains unknown. In this study, we found that miR-506-3p enhanced glucose uptake by 2-deoxy-D-glucose uptake assays and regulated the protein expression of key genes involved in the PI3K/AKT insulin signaling pathway including IRS1, PI3K, AKT, and GlUT4. We next predicted ribosomal protein S6 kinase B1 (S6K1) to be a candidate target of miR-506-3p by bioinformatics analysis and confirmed using dual-luciferase assays that miR-506-3p regulated S6K1 expression by binding to its 3′-UTR. Moreover, modulating S6K1 expression counteracted the effects of miR-506-3p on glucose uptake and PI3K/AKT pathway activation. In conclusion, miR-506-3p altered IR in adipocytes by regulating S6K1-mediated PI3K/AKT pathway activation. Taken together, these findings provide novel insights and potential targets for IR therapy.

scholarly journals Local Cortisol Elevation Contributes to Endometrial Insulin Resistance in Polycystic Ovary Syndrome

2018 ◽  
Vol 103 (7) ◽  
pp. 2457-2467 ◽  
Author(s):  
Jia Qi ◽  
Wangsheng Wang ◽  
Qinling Zhu ◽  
Yaqiong He ◽  
Yao Lu ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Polycystic Ovary Syndrome ◽  
Glucose Uptake ◽  
Signaling Pathway ◽  
Insulin Signaling ◽  
Glucose Transporter ◽  
Polycystic Ovary ◽  
Implantation Rate ◽  
Insulin Signaling Pathway ◽  
Ovary Syndrome

Abstract Context Endometrial insulin resistance (IR) may account for the endometrial dysfunction in polycystic ovary syndrome (PCOS). The underlying mechanism remains to be elucidated. Objective To investigate whether the abundance of 11β-hydroxysteroid dehydrogenases (11β-HSDs) 1 and 2 and cortisol as well as the insulin signaling pathway are altered in PCOS endometrium and to clarify the relationship between endometrial IR and local cortisol. Design We measured cortisol and cortisone concentrations, 11β-HSD1 and 11β-HSD2, and core insulin signaling molecules in endometrial biopsies collected from non-PCOS and PCOS with or without IR patients on the seventh day after human chorionic gonadotropin injection. We also studied the effects of cortisol on glucose uptake and the insulin signaling pathway in primary cultured endometrial epithelial cells (EECs). Results The cortisol concentration was elevated, whereas 11β-HSD2 expression was diminished in endometrial biopsies obtained from PCOS with IR patients compared with those from non-PCOS and PCOS without IR patients. The implantation rate was relatively impaired and the endometrial insulin signaling pathway was defective in PCOS with IR patients. In addition, cortisol attenuated insulin-stimulated glucose uptake in EECs, which was mediated by inhibition of Akt phosphorylation and glucose transporter type 4 translocation via induction of phosphatase and tensin homolog deleted on chromosome ten (PTEN). Conclusions Decreased oxidation of cortisol and defects of insulin signaling in endometrium were observed in PCOS with IR patients. The excessive cortisol level, derived from the reduction of 11β-HSD2, might contribute to the development of endometrial IR by inhibiting the insulin signaling pathway via induction of PTEN expression in EECs.

Leucine reduces the duration of insulin-induced PI 3-kinase activity in rat skeletal muscle

2005 ◽  
Vol 288 (1) ◽  
pp. E86-E91 ◽  
Author(s):  
Jamie I. Baum ◽  
Jason C. O'Connor ◽  
Jennifer E. Seyler ◽  
Tracy G. Anthony ◽  
Gregory G. Freund ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Glucose Uptake ◽  
Signaling Pathway ◽  
Translation Initiation ◽  
Insulin Signaling ◽  
Kinase Activity ◽  
Insulin Signaling Pathway ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
The Impact

Leucine (Leu) is known to stimulate translation initiation of protein synthesis at mammalian target of rapamycin (mTOR) in the insulin signaling pathway. However, potential feedback from mTOR to upstream aspects of the insulin signaling pathway remains controversial. This study evaluates the impact of a physiological oral dose of Leu and/or carbohydrate (CHO) on upstream elements of the insulin signaling pathway using phosphatidylinositol 3-kinase (PI 3-kinase) activity and glucose uptake as markers for insulin sensitivity and glucose homeostasis. Rats (∼200 g) were fasted 12 h and administered oral doses of CHO (1.31 g glucose, 1.31 g sucrose), Leu (270 mg), or CHO plus Leu. Animals were killed at 15, 30, 60, and 90 min after treatment. Plasma and gastrocnemius muscles were collected for analyses. Treatments were designed to produce elevated blood glucose and insulin with basal levels of Leu (CHO); elevated Leu with basal levels of glucose and insulin (Leu); or a combined increase of glucose, insulin, and Leu (CHO + Leu). The CHO treatment stimulated PI 3-kinase activity and glucose uptake with no effect on the downstream translation initiation factor eIF4E. Leu alone stimulated the release of the translation initiation factor eIF4E from 4E-BP1 with no effects on PI 3-kinase activity or glucose uptake. The CHO + Leu treatment reduced the magnitude and duration of the PI 3-kinase response but maintained glucose uptake similar to the CHO treatment and eIF4E levels similar to the Leu treatment. These findings demonstrate that Leu reduces insulin-stimulated PI 3-kinase activity while increasing downstream translation initiation and with no effect on net glucose transport in skeletal muscle.

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